The present invention relates to an illumination device. One of such illumination devices is disclosed, for example, in the German document DE 3,013,040. This illumination device is formed as a headlight and has light source, a reflector and a light disc. Moreover, as conventional, this headlight has optically active elements arranged in the path of rays of the light which is sent from the light source and reflected by the reflector. The optically active elements deviate and/or disperse the light which is sent from the light source and reflected by the reflector so that it provides a desired light distribution. The optically active elements are formed as prisms and/or lenses and arranged on the light disc. The optically active elements have a substantial thickness and therefore the weight of the light disc is increased. The optically active elements must be adjusted moreover exactly to the orientation of the light disc or in other words to its inclination and/or turning, so that for different headlights they must be formed differently. Due to different shapes of the light disc, for example rectangular or round shapes, different shaping tools are needed for producing the light discs. These tools form the optically active elements on the light disc and therefore are very expensive. For each headlight type a special light disc is needed, and it is connected with high manufacturing expenses.